CORYDORAS ROBINEAE - My successful hormonal spawning

[sojapat]

Hi Mike , I dont quite agree with some of the things you are saying .
I know this subject is controversial to many.
I dont think the enviromental impact is at issue ?
I think that is another subject maybe ?
But befrore you say that it is the fishermen collecting ornamental fish that protect the enviroment for sustained resorce check out what they did to the Galaxy rasbora habitat.
Also you may want to ask a few of the guys that ship the Puntius what the fishermen do to the rivers to keep the price high on the fish .
Not the normal ? Money makes the world go round .
As for the next I agree that it is all the things you list that cause the fish poulations to decline .. So what do we do about it to reproduce the fish in Larger Numbers to restore a population if that fish is difficult to breed naturaly ?
Ornamental fish are not as in danger for food purposes... Mainly habitat destruction in my experience.
If it is possible to breed naturaly Great.
If it is not an option use hormone for the first spawn then try F1 natural .
Loss of behavior or loss of a species which would be worse ?

[Mike_Noren]

But befrore you say that it is the fishermen collecting ornamental fish that protect the enviroment for sustained resorce check out what they did to the Galaxy rasbora habitat.

The whole "the galaxy rasbora is becoming rare" thing was never true, I have it on good authority it was an intentional ploy to increase the market price of galaxy rasboras; it is not a rare fish. It is even collected and sold literally by the bucket as food. It will eventually become rare or extinct, like all fish that live in shallow waters which are easily drained to produce agricultural land, but capture for the hobby is unlikely to play much of a part in that.

Also you may want to ask a few of the guys that ship the Puntius what the fishermen do to the rivers to keep the price high on the fish .

They don't need to do anything. Rivers all around the world are being dammed and drained and polluted and overfished and poisoned and redirected anyway. Pretty much all fish in tropical fresh water is or will become endangered as human population increases; few if any due to collection for the aquarium trade.

So what do we do about it to reproduce the fish in Larger Numbers to restore a population if that fish is difficult to breed naturaly ?

From an environmental point of view captive fish are effectively dead. Any species which goes extinct in the wild will do so because their environment has been degraded to the point that the species can not maintain a wild population, meaning that there's nowhere to reintroduce any captive bred fish. Hence it is nice to maintain species in captivity, in the unlikely event that human pressure on environment will decrease in the future, but the focus must be on preserving them in the wild.

The sad fact is that there is no room on this planet for animals or plants which do not generate revenue. Any fish must generate revenue or it will be replaced with something - farmland, hydroelectric dams, tilapia - which does. Even generating revenue wont save it if something even more profitable comes around, like the dams in Xingu show, but even a low value is infinitely better than no value.

Ornamental fish are not as in danger for food purposes... Mainly habitat destruction in my experience.

Habitat destruction yes, but destructive fishing methods - e.g. the widespread use of poison and explosives - do threaten a large number of ornamental fish, even though they're generally not the primary target.

Loss of behavior or loss of a species which would be worse ?

I suppose retaining a degenerate species in captivity, even though it would no longer be able to reproduce in the wild even if their environment hadn't been destroyed, may at least remind us what we've lost.

[sojapat]

Hi Mike , I dont want to get to tanggled in this debate ,
The Galaxy rasboras habitat was pretty smashed up , Fishermen Eco friendly?
I was with the guy that introduced them into the hobby 3 weeks ago ,
You are right they arnt endangered ,
He also took me to the fisheries and aquaculture place at the side of the Mekong river where they are breeding Pangasianodon gigas and Probarbus julieni .

A real eye opener .Here is the hatchery

So without experiments in aquaculture
These 2 fishes that make me smile wouldn't be here ?
If the habitats are destroyed should us fishkeepers not try to preserve them for as long as is possible ,By whatever means .
The behavioral aspect is not at issue for me .
Most fish will not be able to act COMPLETLEY naturaly in an aquarium anyway.
I sell both Wild Puntius , Labeo ,Pangasius to name a few , We also sell Hormone SPAWNED fishes of the same species they all act the same in the aquarium.

[Mike_Noren]

Wild collection transfers money from richer countries to poorer countries and thereby provides incentive to preserve natural habitats. I usually give Malawi cichlids as an example: the only reason there still are Malawi cichlids in the wild is because of the trade in wild caught cichlids. Local collectors have repeatedly stopped plans to introduce nile perch, and are presently involved in projects to protect breeding grounds against destructive fishing (trawling and dynamiting).

Captive breeding, by contrast, provides no incentive to protect wild stocks or habitats, does not protect wild stock (as collection for the trade is not a major threat against wild populations) and frequently the producing countries are not the country of origin of the species. Malawi cichlids bred in the Czech republic generate no revenue in Malawi and provide no incentive to protect natural stocks or habitats.

I'm not opposed to captive breeding, but from an environmental protection point of view wild-caught is clearly better than captive-bred. It would be even more so if collection was done in an environmentally-friendly way.

[jimoo]

I'm not opposed to captive breeding, but from an environmental protection point of view wild-caught is clearly better than captive-bred. It would be even more so if collection was done in an environmentally-friendly way.


This may be the case in some limited situations, but it is not in the majority, since a great deal of collection is certainly not done in an environmentally friendly manner (among other factors).

[Mike_Noren]

This may be the case in some limited situations, but it is not in the majority, since a great deal of collection is certainly not done in an environmentally friendly manner (among other factors).

My opinion is that it is the more environmentally friendly alternative despite that most collection now isn't done in an environmentally friendly way.

Because there is nothing environmentally beneficial at all about captive bred fish. It's convenient and produces larger quantities of cheaper fish, but it's not in any way environmentally friendly. It removes no threat and provides no impetus to support struggling wild populations.

[MatsP]

On this point I agree with Mike. If there is an "easy to get" captive bred species, there is absolutely no reason for the native population to "keep" the natural habitato intact. If, on the other hand, the native population is getting good money for catching exotic fish in the habitat, they have (some) incentive to keep that going. That's not to say that the lure of gold in the hills or logging operations will not make a stronger pull than catching fish in the local river, and thus end up destroying the natural habitat.

Catching fish in nature is a very low threat to the natural habitat in comparison to OTHER things that happen in nature. I asked Mark Sabaj at the Catfish Study Group conference the very question "Should be buy wild-caught fish", and he said "Is there any evidence of extinction from capture for aquatic trade?", which I said "Perhaps for Hypancistrus zebra", but even then, it appears that the natural population is lowered, but nowhere near extinct. On the other hand, there are PLENTY of examples of extinction from other habitat destruction, such as damming rivvers, logging (causing land erosion and other problems), gold-mining (mercury and cyanides for exmaple, as well as land erosion/silt going into clear water rivers) and many other human projects.

--
Mats

[DarrellAR]

This was a very interesting discussion. All the remarks seem to have been inbounds; no "argumentum ad hominem". Maintaining a harmonious tone is important but not everything. Well in posting to forums almost everything. One learns more from disagreements sometimes then from rapports. I would agree that those who want to short circuit the learning process and go directly to go--go directly to a successful spawning are usually down the food chain in skill levels. It is obvious that since all fish to survive have to condition up in nature and spawn in nature it it just a matter of learning how to create the conditions and the diet that brings this about in your tanks. I am however in favor of discovering reproduceable results and documenting them for science.

[cartouche]

I really don't know, what happened, but my Robineae again started to fill with eggs. And I didn't use any special food. Only beef heart and cyclops, sometimes tubifex and earthworms. When I observed that males trained the T-position in the front of females, it seemed that it was the right time to inject them again.

On Tuesday I got 90 eggs from 4 stimulated pairs (by far my best result so far) and only 6 eggs were infertile. A big success that unfortunately soon turned into another failure, because all the eggs were destroyed by fungus after mere 2-3 days. So, hopefully next month I will be more successful...

What is very interesting, however, is the fact that only four young females from my new breeding group were gravid; my old big female didn't fill with eggs at all. Hence I think it is better to buy young fish, not old ones.